| // Copyright 2018 The Bazel Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.devtools.build.lib.starlarkbuildapi; |
| |
| import com.google.devtools.build.docgen.annot.GlobalMethods; |
| import com.google.devtools.build.docgen.annot.GlobalMethods.Environment; |
| import com.google.devtools.build.docgen.annot.StarlarkConstructor; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.packages.semantics.BuildLanguageOptions; |
| import com.google.devtools.build.lib.starlarkbuildapi.config.StarlarkConfigApi.BuildSettingApi; |
| import net.starlark.java.annot.Param; |
| import net.starlark.java.annot.ParamType; |
| import net.starlark.java.annot.StarlarkMethod; |
| import net.starlark.java.eval.Dict; |
| import net.starlark.java.eval.EvalException; |
| import net.starlark.java.eval.NoneType; |
| import net.starlark.java.eval.Sequence; |
| import net.starlark.java.eval.StarlarkCallable; |
| import net.starlark.java.eval.StarlarkFunction; |
| import net.starlark.java.eval.StarlarkThread; |
| |
| /** |
| * Interface for a global Starlark library containing rule-related helper and registration |
| * functions. |
| */ |
| @GlobalMethods(environment = Environment.BZL) |
| public interface StarlarkRuleFunctionsApi { |
| |
| String EXEC_COMPATIBLE_WITH_PARAM = "exec_compatible_with"; |
| String TOOLCHAINS_PARAM = "toolchains"; |
| |
| String PROVIDES_DOC = |
| "A list of providers that the implementation function must return." // |
| + "<p>It is an error if the implementation function omits any of the types of providers" |
| + " listed here from its return value. However, the implementation function may return" |
| + " additional providers not listed here." // |
| + "<p>Each element of the list is an <code>*Info</code> object returned by <a" |
| + " href='../globals/bzl.html#provider'><code>provider()</code></a>, except that a legacy" |
| + " provider is represented by its string name instead.When a target of the rule is used" |
| + " as a dependency for a target that declares a required provider, it is not necessary" |
| + " to specify that provider here. It is enough that the implementation function returns" |
| + " it. However, it is considered best practice to specify it, even though this is not" |
| + " required. The <a" |
| + " href='../globals/bzl.html#aspect.required_providers'><code>required_providers</code></a>" |
| + " field of an <a href='../globals/bzl.html#aspect'>aspect</a> does, however, require" |
| + " that providers are specified here."; |
| |
| @StarlarkMethod( |
| name = "provider", |
| doc = |
| "Defines a provider symbol. The result of this function must be stored in a global value." |
| + " The provider may be instantiated by calling it, or used" |
| + " directly as a key for retrieving an instance of that provider from a target." |
| + " Example:<br><pre class=\"language-python\">" // |
| + "MyInfo = provider()\n" |
| + "...\n" |
| + "def _my_library_impl(ctx):\n" |
| + " ...\n" |
| + " my_info = MyInfo(x = 2, y = 3)\n" |
| + " # my_info.x == 2\n" |
| + " # my_info.y == 3\n" |
| + " ..." // |
| + "</pre><p>See <a href='https://bazel.build/extending/rules#providers'>Rules" |
| + " (Providers)</a> for a comprehensive guide on how to use providers." // |
| + "<p>Returns a <a href='../builtins/Provider.html'><code>Provider</code></a>" |
| + " callable value if <code>init</code> is not specified." // |
| + "<p>If <code>init</code> is specified, returns a tuple of 2 elements: a <a" |
| + " href='../builtins/Provider.html'><code>Provider</code></a> callable value and a" |
| + " <em>raw constructor</em> callable value. See <a" |
| + " href='https://bazel.build/extending/rules#custom_initialization_of_providers'>" |
| + " Rules (Custom initialization of custom providers)</a> and the discussion of the" |
| + " <code>init</code> parameter below for details.", |
| parameters = { |
| @Param( |
| name = "doc", |
| named = true, |
| allowedTypes = { |
| @ParamType(type = String.class), |
| @ParamType(type = NoneType.class), |
| }, |
| defaultValue = "None", |
| doc = |
| "A description of the provider that can be extracted by documentation generating" |
| + " tools."), |
| @Param( |
| name = "fields", |
| doc = |
| "If specified, restricts the set of allowed fields. <br>Possible values are:<ul> " |
| + " <li> list of fields:<br> <pre" |
| + " class=\"language-python\">provider(fields = ['a', 'b'])</pre><p> <li>" |
| + " dictionary field name -> documentation:<br> <pre" |
| + " class=\"language-python\">provider(\n" |
| + " fields = { 'a' : 'Documentation for a', 'b' : 'Documentation for b'" |
| + " })</pre></ul>All fields are optional.", |
| allowedTypes = { |
| @ParamType(type = Sequence.class, generic1 = String.class), |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| positional = false, |
| defaultValue = "None"), |
| @Param( |
| name = "init", |
| doc = |
| "An optional callback for preprocessing and validating the provider's field values" |
| + " during instantiation. If <code>init</code> is specified," |
| + " <code>provider()</code> returns a tuple of 2 elements: the normal provider" |
| + " symbol and a <em>raw constructor</em>." // |
| + "<p>A precise description follows; see <a href='" |
| + "https://bazel.build/extending/rules#custom_initialization_of_providers'>" |
| + "Rules (Custom initialization of providers)</a>" |
| + " for an intuitive discussion and use cases." // |
| + "<p>Let <code>P</code> be the provider symbol created by calling" |
| + " <code>provider()</code>. Conceptually, an instance of <code>P</code> is" |
| + " generated by calling a default constructor function <code>c(*args," |
| + " **kwargs)</code>, which does the following:" // |
| + "<ul>" // |
| + "<li>If <code>args</code> is non-empty, an error occurs.</li>" // |
| + "<li>If the <code>fields</code> parameter was specified when" |
| + " <code>provider()</code> was called, and if <code>kwargs</code> contains any" |
| + " key that was not listed in <code>fields</code>, an error occurs.</li>" // |
| + "<li>Otherwise, <code>c</code> returns a new instance that has, for each" |
| + " <code>k: v</code> entry in <code>kwargs</code>, a field named" |
| + " <code>k</code> with value <code>v</code>." // |
| + "</ul>" // |
| + "In the case where an <code>init</code> callback is <em>not</em> given, a" |
| + " call to the symbol <code>P</code> itself acts as a call to the default" |
| + " constructor function <code>c</code>; in other words, <code>P(*args," |
| + " **kwargs)</code> returns <code>c(*args, **kwargs)</code>. For example," // |
| + "<pre class=\"language-python\">" // |
| + "MyInfo = provider()\n" // |
| + "m = MyInfo(foo = 1)" // |
| + "</pre>" // |
| + "will straightforwardly make it so that <code>m</code> is a" |
| + " <code>MyInfo</code> instance with <code>m.foo == 1</code>." // |
| + "<p>But in the case where <code>init</code> is specified, the call" |
| + " <code>P(*args, **kwargs)</code> will perform the following steps" |
| + " instead:" // |
| + "<ol>" // |
| + "<li>The callback is invoked as <code>init(*args, **kwargs)</code>, that is," |
| + " with the exact same positional and keyword arguments as were passed to" |
| + " <code>P</code>.</li>" // |
| + "<li>The return value of <code>init</code> is expected to be a dictionary," |
| + " <code>d</code>, whose keys are field name strings. If it is not, an error" |
| + " occurs.</li>" // |
| + "<li>A new instance of <code>P</code> is generated as if by calling the" |
| + " default constructor with <code>d</code>'s entries as keyword arguments, as" |
| + " in <code>c(**d)</code>.</li>" // |
| + "</ol>" // |
| + "<p>NB: the above steps imply that an error occurs if <code>*args</code> or" |
| + " <code>**kwargs</code> does not match <code>init</code>'s signature, or the" |
| + " evaluation of <code>init</code>'s body fails (perhaps intentionally via a" |
| + " call to <a href=\"../globals/all.html#fail\"><code>fail()</code></a>), or" |
| + " if the return value of <code>init</code> is not a dictionary with the" |
| + " expected schema." // |
| + "<p>In this way, the <code>init</code> callback generalizes normal provider" |
| + " construction by allowing positional arguments and arbitrary logic for" |
| + " preprocessing and validation. It does <em>not</em> enable circumventing the" |
| + " list of allowed <code>fields</code>." // |
| + "<p>When <code>init</code> is specified, the return value of" |
| + " <code>provider()</code> becomes a tuple <code>(P, r)</code>, where" |
| + " <code>r</code> is the <em>raw constructor</em>. In fact, the behavior of" |
| + " <code>r</code> is exactly that of the default constructor function" |
| + " <code>c</code> discussed above. Typically, <code>r</code> is bound to a" |
| + " variable whose name is prefixed with an underscore, so that only the" |
| + " current .bzl file has direct access to it:" // |
| + "<pre class=\"language-python\">" // |
| + "MyInfo, _new_myinfo = provider(init = ...)" // |
| + "</pre>", |
| named = true, |
| allowedTypes = { |
| @ParamType(type = StarlarkCallable.class), |
| @ParamType(type = NoneType.class), |
| }, |
| positional = false, |
| defaultValue = "None"), |
| }, |
| useStarlarkThread = true) |
| Object provider(Object doc, Object fields, Object init, StarlarkThread thread) |
| throws EvalException; |
| |
| @StarlarkMethod( |
| name = "macro", |
| documented = false, // TODO(#19922): Document |
| parameters = { |
| @Param( |
| name = "implementation", |
| positional = false, |
| named = true, |
| documented = false // TODO(#19922): Document |
| ), |
| @Param( |
| name = "attrs", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| }, |
| named = true, |
| positional = false, |
| defaultValue = "{}", |
| doc = |
| """ |
| A dictionary of the attributes this macro supports, analogous to <a href="#rule.attrs">rule.attrs |
| </a>. Keys are attribute names, and values are attribute objects like <code>attr.label_list(...) |
| </code> (see the <a href=\"../toplevel/attr.html\">attr</a> module). |
| |
| <p>The special <code>name</code> attribute is predeclared and must not be included in the |
| dictionary. There are also reserved attribute names that must not be included: |
| <code>visibility</code>, <code>deprecation</code>, <code>tags</code>, <code>testonly</code>, and |
| <code>features</code>. |
| |
| <p>Attributes whose names start with <code>_</code> are private -- they cannot be passed at the call |
| site of the rule. Such attributes can be assigned a default value (as in |
| <code>attr.label(default="//pkg:foo")</code>) to create an implicit dependency on a label. |
| |
| <p>Certain APIs are not available within symbolic macros. These include: |
| <ul> |
| <li>package(), licenses() |
| <li>environment_group() |
| <li>glob(), subpackages() |
| <li>existing_rules(), existing_rule(), |
| <li>(for WORKSPACE threads) workspace(), register_toolchains(), |
| register_execution_platforms(), bind(), repository rule instantiation |
| </ul> |
| |
| <p>To limit memory usage, there is a cap on the number of attributes that may be declared. |
| """), |
| // TODO: #19922 - Make a concepts page for symbolic macros, migrate some details like the |
| // list of disallowed APIs to there. |
| // TODO: #19922 - Make good on the above threat of enforcing a cap on the number of |
| // attributes. |
| @Param( |
| name = "doc", |
| positional = false, |
| named = true, |
| allowedTypes = { |
| @ParamType(type = String.class), |
| @ParamType(type = NoneType.class), |
| }, |
| defaultValue = "None", |
| doc = |
| "A description of the macro that can be extracted by documentation generating " |
| + "tools.") |
| }, |
| useStarlarkThread = true) |
| StarlarkCallable macro( |
| StarlarkFunction implementation, Dict<?, ?> attrs, Object doc, StarlarkThread thread) |
| throws EvalException; |
| |
| @StarlarkMethod( |
| name = "rule", |
| doc = |
| "Creates a new rule, which can be called from a BUILD file or a macro to create targets." |
| + "<p>Rules must be assigned to global variables in a .bzl file; the name of the " |
| + "global variable is the rule's name." |
| + "<p>Test rules are required to have a name ending in <code>_test</code>, while all " |
| + "other rules must not have this suffix. (This restriction applies only to rules, " |
| + "not to their targets.)", |
| parameters = { |
| @Param( |
| name = "implementation", |
| named = true, |
| doc = |
| "the Starlark function implementing this rule, must have exactly one parameter: <a" |
| + " href=\"../builtins/ctx.html\">ctx</a>. The function is called during the" |
| + " analysis phase for each instance of the rule. It can access the attributes" |
| + " provided by the user. It must create actions to generate all the declared " |
| + "outputs."), |
| @Param( |
| name = "test", |
| named = true, |
| positional = false, |
| defaultValue = "unbound", |
| allowedTypes = { |
| @ParamType(type = Boolean.class), |
| }, |
| doc = |
| "Whether this rule is a test rule, that is, whether it may be the subject of a" |
| + " <code>blaze test</code> command. All test rules are automatically" |
| + " considered <a href='#rule.executable'>executable</a>; it is unnecessary" |
| + " (and discouraged) to explicitly set <code>executable = True</code> for a" |
| + " test rule. The value defaults to <code>False</code>. See the <a" |
| + " href='https://bazel.build/extending/rules#executable_rules_and_test_rules'>" |
| + " Rules page</a> for more information."), |
| @Param( |
| name = "attrs", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| }, |
| named = true, |
| positional = false, |
| defaultValue = "{}", |
| doc = |
| "dictionary to declare all the attributes of the rule. It maps from an attribute" |
| + " name to an attribute object (see <a href=\"../toplevel/attr.html\">attr</a>" |
| + " module). Attributes starting with <code>_</code> are private, and can be" |
| + " used to add an implicit dependency on a label. The attribute" |
| + " <code>name</code> is implicitly added and must not be specified. Attributes" |
| + " <code>visibility</code>, <code>deprecation</code>, <code>tags</code>," |
| + " <code>testonly</code>, and <code>features</code> are implicitly added and" |
| + " cannot be overridden. Most rules need only a handful of attributes. To" |
| + " limit memory usage, there is a cap on the number of attributes that may be" |
| + " declared."), |
| // TODO(bazel-team): need to give the types of these builtin attributes |
| @Param( |
| name = "outputs", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| @ParamType(type = StarlarkFunction.class) // a function defined in Starlark |
| }, |
| named = true, |
| positional = false, |
| defaultValue = "None", |
| valueWhenDisabled = "None", |
| disableWithFlag = BuildLanguageOptions.INCOMPATIBLE_NO_RULE_OUTPUTS_PARAM, |
| doc = |
| "This parameter has been deprecated. Migrate rules to use" |
| + " <code>OutputGroupInfo</code> or <code>attr.output</code> instead. <p>A" |
| + " schema for defining predeclared outputs. Unlike <a" |
| + " href='../toplevel/attr.html#output'><code>output</code></a> and <a" |
| + " href='../toplevel/attr.html#output_list'><code>output_list</code></a>" |
| + " attributes, the user does not specify the labels for these files. See the" |
| + " <a href='https://bazel.build/extending/rules#files'>Rules page</a> for more" |
| + " on predeclared outputs.<p>The value of this argument is either a dictionary" |
| + " or a callback function that produces a dictionary. The callback works" |
| + " similar to computed dependency attributes: The function's parameter names" |
| + " are matched against the rule's attributes, so for example if you pass" |
| + " <code>outputs = _my_func</code> with the definition <code>def" |
| + " _my_func(srcs, deps): ...</code>, the function has access to the attributes" |
| + " <code>srcs</code> and <code>deps</code>. Whether the dictionary is" |
| + " specified directly or via a function, it is interpreted as follows.<p>Each" |
| + " entry in the dictionary creates a predeclared output where the key is an" |
| + " identifier and the value is a string template that determines the output's" |
| + " label. In the rule's implementation function, the identifier becomes the" |
| + " field name used to access the output's <a" |
| + " href='../builtins/File.html'><code>File</code></a> in <a" |
| + " href='../builtins/ctx.html#outputs'><code>ctx.outputs</code></a>. The" |
| + " output's label has the same package as the rule, and the part after the" |
| + " package is produced by substituting each placeholder of the form" |
| + " <code>\"%{ATTR}\"</code> with a string formed from the value of the" |
| + " attribute <code>ATTR</code>:<ul><li>String-typed attributes are substituted" |
| + " verbatim.<li>Label-typed attributes become the part of the label after the" |
| + " package, minus the file extension. For example, the label" |
| + " <code>\"//pkg:a/b.c\"</code> becomes <code>\"a/b\"</code>.<li>Output-typed" |
| + " attributes become the part of the label after the package, including the" |
| + " file extension (for the above example, <code>\"a/b.c\"</code>).<li>All" |
| + " list-typed attributes (for example, <code>attr.label_list</code>) used in" |
| + " placeholders are required to have <i>exactly one element</i>. Their" |
| + " conversion is the same as their non-list version" |
| + " (<code>attr.label</code>).<li>Other attribute types may not appear in" |
| + " placeholders.<li>The special non-attribute placeholders" |
| + " <code>%{dirname}</code> and <code>%{basename}</code> expand to those parts" |
| + " of the rule's label, excluding its package. For example, in" |
| + " <code>\"//pkg:a/b.c\"</code>, the dirname is <code>a</code> and the" |
| + " basename is <code>b.c</code>.</ul><p>In practice, the most common" |
| + " substitution placeholder is <code>\"%{name}\"</code>. For example, for a" |
| + " target named \"foo\", the outputs dict <code>{\"bin\":" |
| + " \"%{name}.exe\"}</code> predeclares an output named <code>foo.exe</code>" |
| + " that is accessible in the implementation function as" |
| + " <code>ctx.outputs.bin</code>."), |
| @Param( |
| name = "executable", |
| named = true, |
| positional = false, |
| defaultValue = "unbound", |
| allowedTypes = { |
| @ParamType(type = Boolean.class), |
| }, |
| doc = |
| "Whether this rule is considered executable, that is, whether it may be the subject" |
| + " of a <code>blaze run</code> command. It defaults to <code>False</code>. See" |
| + " the <a" |
| + " href='https://bazel.build/extending/rules#executable_rules_and_test_rules'>" |
| + " Rules page</a> for more information."), |
| @Param( |
| name = "output_to_genfiles", |
| named = true, |
| positional = false, |
| defaultValue = "False", |
| doc = |
| "If true, the files will be generated in the genfiles directory instead of the " |
| + "bin directory. Unless you need it for compatibility with existing rules " |
| + "(e.g. when generating header files for C++), do not set this flag."), |
| @Param( |
| name = "fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the rule requires " |
| + "in target configuration."), |
| @Param( |
| name = "host_fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the rule requires " |
| + "in host configuration."), |
| @Param( |
| name = "_skylark_testable", |
| named = true, |
| positional = false, |
| defaultValue = "False", |
| doc = |
| "<i>(Experimental)</i><br/><br/>If true, this rule will expose its actions for" |
| + " inspection by rules that depend on it via an <code>Actions</code> provider." |
| + " The provider is also available to the rule itself by calling <a" |
| + " href=\"../builtins/ctx.html#created_actions\">ctx.created_actions()</a>." |
| + "<br/><br/>This should only be used for testing the analysis-time behavior of" |
| + " Starlark rules. This flag may be removed in the future."), |
| @Param( |
| name = TOOLCHAINS_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = Object.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "If set, the set of toolchains this rule requires. The list can contain String," |
| + " Label, or StarlarkToolchainTypeApi objects, in any combination. Toolchains" |
| + " will be found by checking the current platform, and provided to the rule" |
| + " implementation via <code>ctx.toolchain</code>."), |
| @Param( |
| name = "incompatible_use_toolchain_transition", |
| defaultValue = "False", |
| named = true, |
| positional = false, |
| doc = "Deprecated, this is no longer in use and should be removed."), |
| @Param( |
| name = "doc", |
| named = true, |
| positional = false, |
| allowedTypes = { |
| @ParamType(type = String.class), |
| @ParamType(type = NoneType.class), |
| }, |
| defaultValue = "None", |
| doc = |
| "A description of the rule that can be extracted by documentation generating " |
| + "tools."), |
| @Param( |
| name = "provides", |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = PROVIDES_DOC), |
| @Param( |
| name = EXEC_COMPATIBLE_WITH_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "A list of constraints on the execution platform that apply to all targets of " |
| + "this rule type."), |
| @Param( |
| name = "analysis_test", |
| named = true, |
| positional = false, |
| defaultValue = "False", |
| doc = |
| "If true, then this rule is treated as an analysis test. <p>Note: Analysis test" |
| + " rules are primarily defined using infrastructure provided in core Starlark" |
| + " libraries. See <a" |
| + " href=\"https://bazel.build/rules/testing#testing-rules\">Testing</a> for" |
| + " guidance. <p>If a rule is defined as an analysis test rule, it becomes" |
| + " allowed to use configuration transitions defined using <a" |
| + " href=\"#analysis_test_transition\">analysis_test_transition</a> on its" |
| + " attributes, but opts into some restrictions: <ul><li>Targets of this rule" |
| + " are limited in the number of transitive dependencies they may have. <li>The" |
| + " rule is considered a test rule (as if <code>test=True</code> were set)." |
| + " This supersedes the value of <code>test</code></li> <li>The rule" |
| + " implementation function may not register actions. Instead, it must register" |
| + " a pass/fail result via providing <a" |
| + " href='../providers/AnalysisTestResultInfo.html'>AnalysisTestResultInfo</a>.</li></ul>"), |
| @Param( |
| name = "build_setting", |
| allowedTypes = { |
| @ParamType(type = BuildSettingApi.class), |
| @ParamType(type = NoneType.class), |
| }, |
| defaultValue = "None", |
| named = true, |
| positional = false, |
| doc = |
| "If set, describes what kind of <a href='${link" |
| + " config#user-defined-build-settings}'><code>build setting</code></a> this" |
| + " rule is. See the <a href='../toplevel/config.html'><code>config</code></a>" |
| + " module. If this is set, a mandatory attribute named" |
| + " \"build_setting_default\" is automatically added to this rule, with a type" |
| + " corresponding to the value passed in here."), |
| @Param( |
| name = "cfg", |
| defaultValue = "None", |
| named = true, |
| positional = false, |
| doc = |
| "If set, points to the configuration transition the rule will " |
| + "apply to its own configuration before analysis."), |
| @Param( |
| name = "exec_groups", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| defaultValue = "None", |
| positional = false, |
| doc = |
| "Dict of execution group name (string) to <a" |
| + " href='../globals/bzl.html#exec_group'><code>exec_group</code>s</a>. If set," |
| + " allows rules to run actions on multiple execution platforms within a" |
| + " single target. See <a href='${link exec-groups}'>execution groups" |
| + " documentation</a> for more info."), |
| @Param( |
| name = "initializer", |
| named = true, |
| defaultValue = "None", |
| positional = false, |
| doc = |
| "Experimental: the Stalark function initializing the attributes of the rule. " |
| + "<p>The function is called at load time for each instance of the rule. It's " |
| + "called with <code>name</code> and the values of public attributes defined " |
| + "by the rule (not with generic attributes, for example <code>tags</code>). " |
| + "<p>It has to return a dictionary from the attribute names to the desired " |
| + "values. The attributes that are not returned are unaffected. Returning " |
| + "<code>None</code> as value results in using the default value specified in " |
| + "the attribute definition. " |
| + "<p>Initializers are evaluated before the default values specified in " |
| + "an attribute definition. Consequently, if a parameter in the initializer's " |
| + "signature contains a default values, it overwrites the default from the " |
| + "attribute definition (except if returning <code>None</code>). " |
| + "<p>Similarly, if a parameter in the initializer's signature doesn't have a " |
| + "default, the parameter will become mandatory. It's a good practice to omit " |
| + "default/mandatory settings on an attribute definition in such cases. " |
| + "<p>It's a good practice to use <code>**kwargs</code> for attributes that " |
| + "are not handled." |
| + "<p>In case of extended rules, all initializers are called proceeding from " |
| + "child to ancestors. Each initializer is passed only the public attributes " |
| + "it knows about."), |
| @Param( |
| name = "parent", |
| named = true, |
| defaultValue = "None", |
| positional = false, |
| doc = |
| "Experimental: the Stalark rule that is extended. When set the public" |
| + " attributes are merged as well as advertised providers. The rule matches" |
| + " <code>executable</code> and <code>test</code> from the parent. Values of" |
| + " <code>fragments</code>, <code>toolchains</code>," |
| + " <code>exec_compatible_with</code>, and <code>exec_groups</code> are" |
| + " merged. Legacy or deprecated parameters may not be set. Incoming " |
| + "configuration transition <code>cfg</code> of parent is applied after this" |
| + "rule's incoming configuration."), |
| @Param( |
| name = "extendable", |
| named = true, |
| defaultValue = "None", |
| positional = false, |
| allowedTypes = { |
| @ParamType(type = Boolean.class), |
| @ParamType(type = Label.class), |
| @ParamType(type = String.class), |
| @ParamType(type = NoneType.class), |
| }, |
| doc = |
| "Experimental: A label of an allowlist defining which rules can extending this" |
| + " rule. It can be set also to True/False to always allow/disallow extending." |
| + " Bazel defaults to always allowing extensions."), |
| @Param( |
| name = "subrules", |
| allowedTypes = { |
| @ParamType(type = Sequence.class, generic1 = StarlarkSubruleApi.class), |
| }, |
| named = true, |
| defaultValue = "[]", |
| positional = false, |
| doc = "Experimental: List of subrules used by this rule."), |
| }, |
| useStarlarkThread = true) |
| StarlarkCallable rule( |
| StarlarkFunction implementation, |
| Object testUnchecked, |
| Dict<?, ?> attrs, |
| Object implicitOutputs, |
| Object executableUnchecked, |
| boolean outputToGenfiles, |
| Sequence<?> fragments, |
| Sequence<?> hostFragments, |
| boolean starlarkTestable, |
| Sequence<?> toolchains, |
| boolean useToolchainTransition, |
| Object doc, |
| Sequence<?> providesArg, |
| Sequence<?> execCompatibleWith, |
| boolean analysisTest, |
| Object buildSetting, |
| Object cfg, |
| Object execGroups, |
| Object initializer, |
| Object parentUnchecked, |
| Object extendableUnchecked, |
| Sequence<?> subrules, |
| StarlarkThread thread) |
| throws EvalException; |
| |
| @StarlarkMethod( |
| name = "aspect", |
| doc = |
| "Creates a new aspect. The result of this function must be stored in a global value." |
| + " Please see the <a href=\"https://bazel.build/rules/aspects\">introduction to" |
| + " Aspects</a> for more details.", |
| parameters = { |
| @Param( |
| name = "implementation", |
| named = true, |
| doc = |
| "A Starlark function that implements this aspect, with exactly two parameters: <a" |
| + " href=\"../builtins/Target.html\">Target</a> (the target to which the aspect" |
| + " is applied) and <a href=\"../builtins/ctx.html\">ctx</a> (the rule context" |
| + " which the target is created from). Attributes of the target are available" |
| + " via the <code>ctx.rule</code> field. This function is evaluated during the" |
| + " analysis phase for each application of an aspect to a target."), |
| @Param( |
| name = "attr_aspects", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "List of attribute names. The aspect propagates along dependencies specified in " |
| + "the attributes of a target with these names. Common values here include " |
| + "<code>deps</code> and <code>exports</code>. The list can also contain a " |
| + "single string <code>\"*\"</code> to propagate along all dependencies of a " |
| + "target."), |
| @Param( |
| name = "attrs", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| }, |
| named = true, |
| defaultValue = "{}", |
| doc = |
| "A dictionary declaring all the attributes of the aspect. It maps from an attribute" |
| + " name to an attribute object, like `attr.label` or `attr.string` (see <a" |
| + " href=\"../toplevel/attr.html\">attr</a> module). Aspect attributes are" |
| + " available to implementation function as fields of <code>ctx</code>" |
| + " parameter. <p>Implicit attributes starting with <code>_</code> must have" |
| + " default values, and have type <code>label</code> or" |
| + " <code>label_list</code>. <p>Explicit attributes must have type" |
| + " <code>string</code>, and must use the <code>values</code> restriction." |
| + " Explicit attributes restrict the aspect to only be used with rules that" |
| + " have attributes of the same name, type, and valid values according to the" |
| + " restriction."), |
| @Param( |
| name = "required_providers", |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "This attribute allows the aspect to limit its propagation to only the targets " |
| + "whose rules advertise its required providers. The value must be a " |
| + "list containing either individual providers or lists of providers but not " |
| + "both. For example, <code>[[FooInfo], [BarInfo], [BazInfo, QuxInfo]]</code> " |
| + "is a valid value while <code>[FooInfo, BarInfo, [BazInfo, QuxInfo]]</code> " |
| + "is not valid." |
| + "" |
| + "<p>An unnested list of providers will automatically be converted to a list " |
| + "containing one list of providers. That is, <code>[FooInfo, BarInfo]</code> " |
| + "will automatically be converted to <code>[[FooInfo, BarInfo]]</code>." |
| + "" |
| + "<p>To make some rule (e.g. <code>some_rule</code>) targets visible to an " |
| + "aspect, <code>some_rule</code> must advertise all providers from at least " |
| + "one of the required providers lists. For example, if the " |
| + "<code>required_providers</code> of an aspect are " |
| + "<code>[[FooInfo], [BarInfo], [BazInfo, QuxInfo]]</code>, this aspect can " |
| + "see <code>some_rule</code> targets if and only if " |
| + "<code>some_rule</code> provides <code>FooInfo</code>, <em>or</em> " |
| + "<code>BarInfo</code>, <em>or</em> both <code>BazInfo</code> <em>and</em> " |
| + "<code>QuxInfo</code>."), |
| @Param( |
| name = "required_aspect_providers", |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "This attribute allows this aspect to inspect other aspects. The value must be a " |
| + "list containing either individual providers or lists of providers but not " |
| + "both. For example, <code>[[FooInfo], [BarInfo], [BazInfo, QuxInfo]]</code> " |
| + "is a valid value while <code>[FooInfo, BarInfo, [BazInfo, QuxInfo]]</code> " |
| + "is not valid." |
| + "" |
| + "<p>An unnested list of providers will automatically be converted to a list " |
| + "containing one list of providers. That is, " |
| + "<code>[FooInfo, BarInfo]</code> will automatically be converted to " |
| + "<code>[[FooInfo, BarInfo]]</code>. " |
| + "" |
| + "<p>To make another aspect (e.g. <code>other_aspect</code>) visible to this " |
| + "aspect, <code>other_aspect</code> must provide all providers from at least " |
| + "one of the lists. In the example of " |
| + "<code>[[FooInfo], [BarInfo], [BazInfo, QuxInfo]]</code>, this aspect can " |
| + "see <code>other_aspect</code> if and only if <code>other_aspect</code> " |
| + "provides <code>FooInfo</code>, <em>or</em> <code>BarInfo</code>, " |
| + "<em>or</em> both <code>BazInfo</code> <em>and</em> <code>QuxInfo</code>."), |
| @Param(name = "provides", named = true, defaultValue = "[]", doc = PROVIDES_DOC), |
| @Param( |
| name = "requires", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = StarlarkAspectApi.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = "List of aspects required to be propagated before this aspect."), |
| @Param( |
| name = "fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the aspect requires " |
| + "in target configuration."), |
| @Param( |
| name = "host_fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the aspect requires " |
| + "in host configuration."), |
| @Param( |
| name = TOOLCHAINS_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = Object.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "If set, the set of toolchains this rule requires. The list can contain String," |
| + " Label, or StarlarkToolchainTypeApi objects, in any combination. Toolchains" |
| + " will be found by checking the current platform, and provided to the rule" |
| + " implementation via <code>ctx.toolchain</code>."), |
| @Param( |
| name = "incompatible_use_toolchain_transition", |
| defaultValue = "False", |
| named = true, |
| doc = "Deprecated, this is no longer in use and should be removed."), |
| @Param( |
| name = "doc", |
| named = true, |
| allowedTypes = { |
| @ParamType(type = String.class), |
| @ParamType(type = NoneType.class), |
| }, |
| defaultValue = "None", |
| doc = |
| "A description of the aspect that can be extracted by documentation generating " |
| + "tools."), |
| @Param( |
| name = "apply_to_generating_rules", |
| named = true, |
| positional = false, |
| defaultValue = "False", |
| doc = |
| "If true, the aspect will, when applied to an output file, instead apply to the " |
| + "output file's generating rule. " |
| + "<p>For example, suppose an aspect propagates transitively through attribute " |
| + "`deps` and it is applied to target `alpha`. Suppose `alpha` has " |
| + "`deps = [':beta_output']`, where `beta_output` is a declared output of " |
| + "a target `beta`. Suppose `beta` has a target `charlie` as one of its " |
| + "`deps`. If `apply_to_generating_rules=True` for the aspect, then the aspect " |
| + "will propagate through `alpha`, `beta`, and `charlie`. If False, then the " |
| + "aspect will propagate only to `alpha`. </p><p>False by default.</p>"), |
| @Param( |
| name = EXEC_COMPATIBLE_WITH_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "A list of constraints on the execution platform that apply to all instances of" |
| + " this aspect."), |
| @Param( |
| name = "exec_groups", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| defaultValue = "None", |
| positional = false, |
| doc = |
| "Dict of execution group name (string) to <a" |
| + " href='../globals/bzl.html#exec_group'><code>exec_group</code>s</a>. If set," |
| + " allows aspects to run actions on multiple execution platforms within a" |
| + " single instance. See <a href='${link exec-groups}'>execution groups" |
| + " documentation</a> for more info."), |
| @Param( |
| name = "subrules", |
| allowedTypes = { |
| @ParamType(type = Sequence.class, generic1 = StarlarkSubruleApi.class), |
| }, |
| named = true, |
| defaultValue = "[]", |
| positional = false, |
| doc = "Experimental: list of subrules used by this aspect.") |
| }, |
| useStarlarkThread = true) |
| StarlarkAspectApi aspect( |
| StarlarkFunction implementation, |
| Sequence<?> attributeAspects, |
| Dict<?, ?> attrs, |
| Sequence<?> requiredProvidersArg, |
| Sequence<?> requiredAspectProvidersArg, |
| Sequence<?> providesArg, |
| Sequence<?> requiredAspects, |
| Sequence<?> fragments, |
| Sequence<?> hostFragments, |
| Sequence<?> toolchains, |
| boolean useToolchainTransition, |
| Object doc, |
| Boolean applyToGeneratingRules, |
| Sequence<?> execCompatibleWith, |
| Object execGroups, |
| Sequence<?> subrules, |
| StarlarkThread thread) |
| throws EvalException; |
| |
| @StarlarkMethod( |
| name = "Label", |
| doc = |
| "Converts a label string into a <code>Label</code> object, in the context of the package" |
| + " where the calling <code>.bzl</code> source file lives. If the given value is" |
| + " already a <code>Label</code>, it is returned unchanged.<p>For macros, a related" |
| + " function, <code><a" |
| + " href='../toplevel/native.html#package_relative_label'>native.package_relative_label()</a></code>," |
| + " converts the input into a <code>Label</code> in the context of the package" |
| + " currently being constructed. Use that function to mimic the string-to-label" |
| + " conversion that is automatically done by label-valued rule attributes.", |
| parameters = { |
| @Param( |
| name = "input", |
| allowedTypes = {@ParamType(type = String.class), @ParamType(type = Label.class)}, |
| doc = |
| "The input label string or Label object. If a Label object is passed, it's" |
| + " returned as is.") |
| }, |
| useStarlarkThread = true) |
| @StarlarkConstructor |
| Label label(Object input, StarlarkThread thread) throws EvalException; |
| |
| @StarlarkMethod( |
| name = "exec_group", |
| doc = |
| "Creates an <a href='${link exec-groups}'>execution group</a> which can be used to" |
| + " create actions for a specific execution platform during rule implementation.", |
| parameters = { |
| @Param( |
| name = TOOLCHAINS_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = Object.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "The set of toolchains this execution group requires. The list can contain String," |
| + " Label, or StarlarkToolchainTypeApi objects, in any combination."), |
| @Param( |
| name = EXEC_COMPATIBLE_WITH_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = "A list of constraints on the execution platform."), |
| }, |
| useStarlarkThread = true) |
| ExecGroupApi execGroup( |
| Sequence<?> toolchains, Sequence<?> execCompatibleWith, StarlarkThread thread) |
| throws EvalException; |
| |
| @StarlarkMethod( |
| name = "subrule", |
| doc = |
| "Constructs a new instance of a subrule. The result of this function must be stored in " |
| + "a global variable before it can be used.", |
| parameters = { |
| @Param( |
| name = "implementation", |
| doc = "The Starlark function implementing this subrule", |
| named = true, |
| positional = false, |
| allowedTypes = {@ParamType(type = StarlarkFunction.class)}), |
| @Param( |
| name = "attrs", |
| allowedTypes = {@ParamType(type = Dict.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "{}", |
| doc = |
| "A dictionary to declare all the (private) attributes of the subrule. " |
| + "<p/>Subrules may only have private attributes that are label-typed (i.e. " |
| + "label or label-list). The resolved values corresponding to these labels are" |
| + " automatically passed by Bazel to the subrule's implementation function as" |
| + " named arguments (thus the implementation function is required to accept" |
| + " named parameters matching the attribute names). The types of these values" |
| + " will be: " |
| + "<ul><li><code>FilesToRunProvider</code> for label attributes with" |
| + " <code>executable=True</code></li>" |
| + "<li><code>File</code> for label attributes" |
| + " with <code>allow_single_file=True</code></li>" |
| + "<li><code>Target</code> for" |
| + " all other label attributes</li>" |
| + "<li><code>[Target]</code> for all label-list" |
| + " attributes</li></ul>"), |
| @Param( |
| name = "toolchains", |
| allowedTypes = {@ParamType(type = Sequence.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "If set, the set of toolchains this subrule requires. The list can contain String," |
| + " Label, or StarlarkToolchainTypeApi objects, in any combination. Toolchains" |
| + " will be found by checking the current platform, and provided to the subrule" |
| + " implementation via <code>ctx.toolchains</code>."), |
| @Param( |
| name = "fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the subrule requires in target" |
| + " configuration."), |
| @Param( |
| name = "subrules", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = StarlarkSubruleApi.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = "List of other subrules needed by this subrule.") |
| }, |
| useStarlarkThread = true) |
| StarlarkSubruleApi subrule( |
| StarlarkFunction implementation, |
| Dict<?, ?> attrs, |
| Sequence<?> toolchains, |
| Sequence<?> fragments, |
| Sequence<?> subrules, |
| StarlarkThread thread) |
| throws EvalException; |
| } |
